The real difference between RH ANAYLSER PRO and STOPCLOCK PROFESSIONAL

[Luis-F-S]

The videos also explain the functionalities quite well:

http://www.beyondmonochrome.co.uk/ma...t/Archive.html

L

[sperdynamite]

I have an analyser pro and the workflow is quite different than with the Stopclock. In some ways it's faster to get to a reasonably good print. Really fast actually, the analyser is very accurate after calibration. However, once you get that 'pretty good' print, it's a bit more challenging to then move to a perfect print. The analyser does have some automation should you want to do burns which is nice, but it's not as friendly with split grade printing. It seems like the Stopclock makes splitgrade a breeze.

I've only just finished calibrating my Analyser. I am using Ilford MG Classic glossy, Ansco 130, and a Heiland LED. It took a lot of printing sessions to really nail calibration, partly due to user error as the process isn't super intuitive at first. There are lots of ways to make little mistakes that throw off the whole system. After I had my calibration data though I pretty quickly made 3 prints from 3 different negatives. They look good, and with the last one I began exploring the 'difference' burn mode. I can't help but think though that maybe the Stopclock was the better choice for me. The Heiland Splitgrade anaylser is out of my price range, and the Stopclock would make this process easier than with the Analyser Pro. Spitgrade printing is a pretty powerful tool for many negatives, plus creative dodging and burning, etc. During calibration I couldn't help but think, WTH am I doing? I could just be PRINTING. I think the 'promise' of the Analyser Pro is that you can make prints easily with no or a minimum of test strips, which it delivers on I think. But if you are the kind of printer who really works a negative creatively, it may not be the best choice.

I'll stick with mine for a bit, but don't be surprised if you see a WTT ad from me. At the end of the day, printing is challenging. A real art and science. Analysers can help with one area but make others harder. Maybe someone with the Heiland Splitgrade feels differently, I haven't used one.

[SilverPr]

I have an analyser pro and the workflow is quite different than with the Stopclock. In some ways it's faster to get to a reasonably good print. Really fast actually, the analyser is very accurate after calibration. However, once you get that 'pretty good' print, it's a bit more challenging to then move to a perfect print. The analyser does have some automation should you want to do burns which is nice, but it's not as friendly with split grade printing. It seems like the Stopclock makes splitgrade a breeze.

I've only just finished calibrating my Analyser. I am using Ilford MG Classic glossy, Ansco 130, and a Heiland LED. It took a lot of printing sessions to really nail calibration, partly due to user error as the process isn't super intuitive at first. There are lots of ways to make little mistakes that throw off the whole system. After I had my calibration data though I pretty quickly made 3 prints from 3 different negatives. They look good, and with the last one I began exploring the 'difference' burn mode. I can't help but think though that maybe the Stopclock was the better choice for me. The Heiland Splitgrade anaylser is out of my price range, and the Stopclock would make this process easier than with the Analyser Pro. Spitgrade printing is a pretty powerful tool for many negatives, plus creative dodging and burning, etc. During calibration I couldn't help but think, WTH am I doing? I could just be PRINTING. I think the 'promise' of the Analyser Pro is that you can make prints easily with no or a minimum of test strips, which it delivers on I think. But if you are the kind of printer who really works a negative creatively, it may not be the best choice.

I'll stick with mine for a bit, but don't be surprised if you see a WTT ad from me. At the end of the day, printing is challenging. A real art and science. Analysers can help with one area but make others harder. Maybe someone with the Heiland Splitgrade feels differently, I haven't used one.

Your post helped a lot. One of my hesitations was if Analyser pro can be useful for Splitgrading. And you gave me the answer... my first choice will be Stopclock... And BTW if you decide to sell Analyser drop me a message, my friend dreams about it and looking for second hand one.

[Andrea Gazzoni]

was reading into the manual and playing with my Analyser.
one thing I don't get is how the increments are calculated in this timer.
I start with a base exposure of 15 seconds and set the step progression at 1/3 of stop.
Here I summarized what I get from the Analyser and what my calculations are:



for me, increasing a 15 second exposure by one stop means 30 seconds, not 31.2.
I know the deltas are negligible, but I'm curious to understand how the machine thinks.
Is it maybe incorporating some other compensations like for reciprocity failure? Please note that I didn't look into the any profiling yet, so my assumption that these are the default factory values may prove wrong.

what am I missing here?

[mmerig]

was reading into the manual and playing with my Analyser.
one thing I don't get is how the increments are calculated in this timer.
I start with a base exposure of 15 seconds and set the step progression at 1/3 of stop.
Here I summarized what I get from the Analyser and what my calculations are:



for me, increasing a 15 second exposure by one stop means 30 seconds, not 31.2.
I know the deltas are negligible, but I'm curious to understand how the machine thinks.
Is it maybe incorporating some other compensations like for reciprocity failure? Please note that I didn't look into the any profiling yet, so my assumption that these are the default factory values may prove wrong.

what am I missing here?

I have wondered about the same thing. The uneven time steps seem built-in.

[Deyoung]

I have wondered about the same thing. The uneven time steps seem built-in.

From what I've read, I believe its because the analyzer pro automatically takes into account reciprocity failure for the paper. I can't remember where i read that, but I believe it was on the RH designs website or a Video.

Seems to make sense to me at least.

[mmerig]

Reciprocity failure would vary by paper, so a constant curve in time increments may not work for all papers. But for a wide range of exposures, reciprocity failure in paper is very small. Here is a statement about it from Ilford:

"Paper products are designed for much longer exposure times than film and are less sensitive to reciprocity failure. Whilst there may be a small effect over very long times it is generally not necessary to make any compensation for reciprocity failure on paper products"

The RH Designs manual does not say anything about the time steps being uneven, or an adjustment for RF. I did not see anything about on their website, including the video, but may have missed it.

In the book "Beyond Monochrome", paper reciprocity failure is described in detail, based on actual testing of several papers. The adjustment time was about 1/16 stop per doubling of exposure time, so the proportional increase should be about 1.0625 per doubling, so we would expect an increase around this size for each doubling on the time scale, but the RH timer's proportional amount of increase increases with time, from 1.04 in the 2- to 4-second range to 1.27 in the 64- to 128-second range, at a quadratic pace. Having a built-in adjustment for RF only makes sense if a known exposure works, and a printer wants keep the tonation the same after changing the print size or the iris. But if they have a print that looks underexposed, and guesses that a 1/2-stop increase will make it right, then a timer that does not progress evenly to a 1/2 stop is not optimal.

As mentioned in an earlier post, the timing errors are small. I think a guess would be less precise than the errors anyway, for most people.

I will ask Chris Woodhouse about it.

[Andrea Gazzoni]

Just found this video in which Chris explains this behaviour, it's for reciprocity failure indeed.
Around min 06:35.



The manual says
"The standard built-in calibration suits Ilford Multigrade IV RC paper using a standard enlarger (tungsten/halogen Start a Burn-in Exposure Start / Pause / Resume Exposure lamp and diffuse illumination) and the Ilford Multigrade Filter Set (underor above-lens)"

I find it interesting how their Stopclock logically doesn't have this feature and has a linear progression in which going 1 stop above 15 sec leads you to 30 sec. Different machines with different purposes.

Now to find how to alter the base exposure without going into the user settings or entering linear mode necessarily.

The Analyser comes with a preset of 15 seconds, now say I need to set the base exposure for one test strip sequence at 18 seconds instead of 15. No metering needed.
I can't find a shortcut to override the fstop increment and go precisely to 18 sec. Incrementing 15 by 1/12 fstops fractions does lead to 18 sec in three steps, but I suspect they have thought of a simpler way to achieve this.
It's such a nice machine.

[nolindan]

I'm with Ilford - there is no reciprocity failure in paper. http://www.darkroomautomation.com/su...ermittency.pdf

The write up in Way Beyond Monochrome is in error. A set of reciprocity failure HD curves will show increasing contrast with decreasing light intensity/increasing exposure time - the curves shown in WBM are parallel. It appears to me the effect noted in the book may be due to improper compensation of lamp warm-up time. http://www.darkroomautomation.com/su...2LampDelay.pdf

The RHD numbers make no sense to me. My supposition is there is also a math error, probably as the result of some fudge approximation for exponentiation. A table of differences of the RHD's timer's exposure times shows anomalous values, if you are into that sort of analysis.

The error in the above RHD times is around 1/12 of a stop and insignificant except with high contrast filtration.

[mmerig]

Chris Woodhouse responded to my question. Thank you Chris, and thanks to Andrea for the video reference too.

Here is my question to Chris and his response:

"Hello Mr. Woodhouse,

I have an RH Designs AP, and use it a lot and really like it, but have wondered why the f-stop timing increments are not even or expected (e.g +1 stop from 15 seconds is 31.2, not 30). I don't mind these discrepancies, but someone on the Large Format Photographers forum asked about it, and I made stab at, but also said I would ask you. Would you be so kind and give us some insight about it?

The link on the internet is:

https://www.largeformatphotography.i...ESSIONAL/page2

Responding to me is fine too -- whatever works for you of course.

P.S., I have "Beyond Monochrome" and read the discussion on reciprocity failure in paper. This was very helpful in general but it does not seem to be the reason as others have assumed."

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

"They deliberately include reciprocity compensation. When I designed this we tested several papers and they exhibited similar effects.

Sent from my iPhone"

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Furthermore, I agree with nolindan -- the RHD numbers don't make sense given a small reciprocity error, and it is hard to see why the correction factor increases with time, when it is claimed to be nearly constant for a given paper, and similar for many papers.


I don't mind the uneven spacing, but now that i think of it, a true f-stop progression would be preferable, and I think the correction becomes to great at higher time intervals. But for those out there wondering about the RHD AP, it is a great tool and I have used it for hundreds of prints and saved countless hours and paper.